This patent application claims priority based on a Japanese patent application, 2000-304245 filed on Oct. 3, 2000, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a semiconductor device manufacturing system and an electron beam exposure apparatus. More particularly, the present invention relates to a semiconductor device manufacturing system that exposes a wafer using a plurality of electron beams having a preferred interval of separation to manufacture a semiconductor device.
2. Description of the Related Art
A conventional electron beam exposure apparatus that performs an exposure process using a plurality of electron beams irradiates a plurality of electron beams, which are separated from each other with a constant interval, on a wafer and forms an exposure pattern on the wafer. The conventional electron beam exposure apparatus stores all exposure pattern data of the chip to be provided on the wafer and provides to the control system, which controls each of the plurality of electron beams, the individual exposure pattern data based on the stored exposure pattern data. The individual exposure pattern data is an exposure pattern data in the regions where each of the plurality of electron beams should expose. The control system performs exposure process to the wafer based on the individual exposure pattern data by controlling each electron beam.
The conventional electron beam exposure apparatus further has a storing unit that stores an individual exposure pattern data that is extracted from all the exposure pattern data for each of the plurality of electron beams. The storing unit requires a very high-speed semiconductor memory, for example.
The degree of integration of elements such as transistors in an electron device has increased recently. Accordingly, the amount of exposure pattern data, which has to be exposed on the wafer for one electron device, has become large. Thus, a problem occurs such that the conventional electron beam exposure apparatus becomes extremely expensive because the conventional electron beam exposure apparatus requires a storing unit, such as an extremely high-speed semiconductor memory, having a large capacity to store the individual exposure pattern data.
Furthermore, the conventional electron beam exposure apparatus needs to expose one chip by a plurality of electron beams even when the width of the chip to be provided on the wafer is smaller than the interval, i.e. spacing, between the plurality of electron beams. Thus, a problem occurs such that misregistration of the exposure pattern occurs at the boundary between the region where one electron beam exposes one chip and the region where another electron beam, which is adjacent to the just electron beam, exposes the same chip. As a result, the wiring resistance increases or the reliability of the wiring decreases greatly at the place where the misregistration occurs when the exposure pattern is a wiring pattern of the electron device.
Therefore, it is an object of the present invention to provide a semiconductor device manufacturing system and an electron beam exposure apparatus which overcome the above issues in the related art. This object is achieved by combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the present invention.
According to the first aspect of the present invention, a semiconductor device manufacturing system for manufacturing a semiconductor device on a wafer, comprises: a first exposure apparatus for exposing the wafer using a light source while moving the wafer with a predetermined interval; and a second exposure apparatus for exposing the wafer by irradiating a plurality of electron beams on the wafer, said plurality of electron beams having an interval of substantially N times or 1/N times, where N is a natural number, of the predetermined interval.
The second exposure apparatus may have a plurality of multi-axis electron lenses that converge each beam of the plurality of electron beams independently; and each of the multi-axis electron lenses may have a plurality of lens opening parts for said plurality of electron beams to pass through; and the lens opening parts may be separated with an interval of substantially N times or 1/N times of the predetermined interval of the first exposure apparatus for moving the wafer.
Each of the multi-axis electron lens may have a plurality of dummy opening parts, through which the electron beams do not pass, arranged around a periphery of the plurality of lens opening parts. Each of the multi-axis electron lens may have a lens unit that includes the lens opening parts; and the lens opening parts may be arranged to be uniformly distributed all over the lens unit. Each of the multi-axis electron lens may have a lens unit that includes the lens opening parts; and the lens opening parts may be arranged in the lens unit in a belt-like shape. The lens opening parts at a center region of the lens unit may have a diameter that is smaller than the diameter of the lens opening parts at an outer region of the lens unit.
The lens unit may include a first lens-part magnetic conductive member and a second lens-part magnetic conductive member that are arranged substantially parallel to each other with a space in between; and the lens unit may further include a nonmagnetic conductive member in the space between the first lens-part magnetic conductive member and the second lens-part magnetic conductive member.
Each of the multi-axis electron lens may have a lens unit that includes the lens opening parts and a coil unit provided around the lens unit for generating magnetic fields; and the coil unit may include a coil part magnetic conductive member, which is a magnetic conductive member, and a coil for generating the magnetic fields; and the lens unit may include a plurality of lens-part magnetic conductive members, which are magnetic conductive members; and magnetic permeability of a material that forms the coil-part magnetic conductive member and magnetic permeability of a material that forms the lens-part magnetic conductive members may be different.
The second exposure apparatus may have a plurality of deflectors that deflect each beam of the plurality of electron beams independently; and the deflectors may be separated with an interval of substantially N times or 1/N times of the predetermined interval.
According to the second aspect of the present invention, an electron beam exposure apparatus for exposing a wafer, in combination with exposure by an optical stepper, using a plurality of electron beams, comprises: an exposure unit for exposing the wafer by irradiating the plurality of electron beams on the wafer, the plurality of electron beams having an interval of substantially N times or 1/N times, where N is a natural number, of a predetermined interval of the optical stepper for moving the wafer.
The exposure unit may have a plurality of multi-axis electron lenses that converges each beam of the plurality of electron beams independently; and each of the multi-axis electron lenses may have a plurality of lens opening parts for passage of the plurality of electron beams; and the lens opening parts may be separated with an interval of substantially N times or 1/N times of said predetermined interval.
Each of the multi-axis electron lens may have a plurality of dummy opening parts, through which the electron beams do not pass, arranged around a periphery of the plurality of lens opening parts. Each of the multi-axis electron lens may have a lens unit that includes a plurality of the lens opening parts; and the lens opening parts may be arranged to be substantially uniform all over the lens unit.
Each of the multi-axis electron lens may have a lens unit that includes the lens opening parts; and the lens opening parts may be provided in the lens unit such that the lens opening parts form belt-like shape. The lens opening parts at a center region of the lens unit may have a diameter that is smaller than the diameter of the lens opening parts at an outer region of the lens unit.
The lens unit may include a first lens-part magnetic conductive member and a second lens-part magnetic conductive member that are arranged substantially parallel to each other with a space in between; and the lens unit may further include a nonmagnetic conductive member in the space between the first lens-part magnetic conductive member and the second lens-part magnetic conductive member.
Each of the multi-axis electron lens may have a lens unit that includes the lens opening parts and a coil unit provided around the lens unit for generating magnetic fields; and the coil unit may include a coil part magnetic conductive member, which is a magnetic conductive member, and a coil for generating the magnetic fields; and the lens unit may include a plurality of lens-part magnetic conductive members, which are magnetic conductive members; and magnetic permeability of a material that forms the coil-part magnetic conductive member and magnetic permeability of a material that forms the lens-part magnetic conductive members may be different.
The exposure unit may have a plurality of deflectors that deflect each beam of the plurality of electron beams independently; and the deflectors are separated with an interval of substantially N times or 1/N times of the predetermined interval.
According to the third aspect of the present invention, a method for manufacturing a semiconductor device on a wafer, comprises steps of: exposing the wafer using a light source while moving the wafer with a predetermined interval; and exposing the wafer by irradiating a plurality of electron beams on the wafer, said plurality of electron beams having an interval of substantially N times or 1/N times, where N is a natural number, of the predetermined interval.
This summary of the invention does not necessarily describe all necessary features of the present invention. The present invention may also be a sub-combination of the above described features. The above and other features and advantages of the present invention will become more apparent from the following description of embodiments taken in conjunction with the accompanying drawings.